BR112020008743A2 - stretch laminate - Google Patents

Abstract

The present invention relates to a stretchable laminate for use in hygiene products, including: a non-elastic, extensible melt spinning or continuous spinning nonwoven laminated with an elastic film; and the stretchable laminate is activated, has a 10 N crosswise elongation (CD) in a range of 80 to 150% for a 50 mm wide sample, and has less than 10% breaks in the stretchable laminate.

Description

STREAMABLE LAMINATE Related Patent Application

[001] This application claims the benefit of copending US provisional Patent Application No. 62 / 578,644 filed on October 30, 2017, hereby incorporated by reference. Field of the Invention

[002] The invention relates to stretch laminates, particularly to stretch laminates used in hygiene products.

Foundations

[003] Stretch laminates are used, for example, in the production of hygiene products. Hygiene products may include, but are not limited to: diapers, absorbent items, training pants, diapers for older children, adult incontinence products and the like. For example, see Document US7794819 and the references cited therein, each of which is incorporated herein by reference in its entirety.

[004] In general, a stretchable laminate can be a structure having two or three layers laminated together, so that the laminated structure is elastic (for example, stretchable and recoverable) in at least one direction. The two-layer laminate usually includes a non-woven fabric laminated with an elastic film, and the three-layer laminate “typically includes two non-woven fabrics interleaving the elastic film.

[005] Stretch laminates can be used as various components of the hygiene product (for example, elements that connect the front and rear absorbent parts of the hygiene product in a removable or fixed way). In one example, stretch laminate is used to form the “side panel ears” and / or 'flaps' of the hygiene product. The ears and / or side panel flaps are used to secure the hygiene product around the Normally, the ears and / or flaps on the side panel are affixed to the rear sides of hygiene products and can be removably attached to the front of the hygiene product (or fixedly attached) when the product is in use by the user.

[006] These ears or flaps on the side panel are generally elastic. The elasticity of the ears or flaps on the side panel helps ensure a safe and comfortable fit of the hygiene product to the user. In use, for example, the ears or flaps on the side panel can be stretched from the back of the product and around the user and are removably attached to the front of the product, and the ears or flaps on the side panel retract to provide safe and comfortable fit for the user.

[007] As the stretch laminates used in hygiene products have evolved over time, for example, to improve quality and reduce price, a preferred nonwoven is a nonwoven produced by continuous spinning (spunbound) or spinning by melting ( spunmelt). While stretch laminates made with non-woven continuous spinning or melt spinning meet the needs for use in these hygiene products, stretch laminates of this type can be improved.

[008] For example, when stretch laminates made with continuous spinning or melt spinning nonwoven are stretched during manufacture (e.g.

activation), the nonwoven may break. To understand the break (or break), see Figure 1. In Figure 1, a continuous spinning nonwoven from the state of the art has been stretched, the breaks appear as dark areas where the continuous spinning nonwoven has broken (that is, the nonwoven fibers have separated or detached). When this rupture occurs, the elastic layer of the stretch laminate is exposed. Exposure of the elastic layer is not preferred and gives the feeling of poor quality of the product or product degraded / corrupted or the feeling that the product will break / break.

[009] Thus, there is a need for a stretch laminate in which the nonwoven of continuous spinning or melt spinning does not break (or the amount of rupture is reduced) when the stretch laminate is stretched (for example, during activation and / or later use).

Summary of the Invention

[010] A stretchable laminate for use in hygiene products includes: a non-elastic, extensible melt spinning or continuous spinning nonwoven laminated with an elastic film; and the stretch laminate is activated, has a 10 N cross-sectional elongation (CD) in a range of 80 to 150% for a 50 mm wide sample, and has less than 10% breaks in the stretch laminate. Description of the Figures

[011] In order to illustrate the invention, a currently preferred form is shown in the drawings; it being understood, however, that this invention is not limited to the arrangements and instruments precisely shown.

[012] Figure 1 illustrates a stretchable laminate produced with a continuous spinning or melt spinning nonwoven of the prior art, showing breaks in the nonwoven in a stretched state.

[013] Figure 2 illustrates the invention, a stretch laminate produced with a continuous spinning or melt spinning nonwoven, which has no breaks in a stretched state.

[014] Figure 3 is a graph that illustrates a stress-strain curve, where the X axis is the% deformation and the Y axis is the force (N).

[015] Figures 4A and 4b illustrate an embodiment of activation by a ring roller; Figure 4A is a representative ring cylinder and Figure 4B illustrates a non-interlacing of the rings (left side) and an interlacing of the rings (left side).

[016] Figures 5A and 5B are graphs that illustrate the maximum load of the stretch laminate and elastic film.

[017] Figures 6A, 6B and 6C illustrate the procedure established here for measuring breaks.

[018] Figures 7A and 7b illustrate the concept of a broken nonwoven, Figure 7A, and an unbroken nonwoven, Figure 7B.

Description of the Invention

[019] The invention relates to a stretch laminate, particularly a stretch laminate used in a hygiene product, and, more particularly, a stretch laminate used as an ear or side panel flap in a hygiene product.

[020] By means of this invention, breaks can be reduced or eliminated by providing a nonwoven stretch laminate having specific properties, discussed below. The inventive stretch laminate is a stretch laminate in which a nonwoven (for example, a continuous spinning or melt spinning nonwoven) does not break (or the amount of breakage is reduced) when the stretch laminate is stretched (for example , during activation and / or later use). To understand non-breakage, compare Figure 1 and Figure 2. Figure 1 illustrates a broken nonwoven, and Figure 2 illustrates an unbroken continuous spinning nonwoven (note that the amount of stretch applied to the stretch laminates in Figure 1 and Figure 2 is the same). In Figure 2, the amount of rupture is reduced (or eliminated). The break will be explained in more detail below.

[021] In general, a stretch laminate can include a layer of non-woven laminate to an elastic layer. The stretch laminate can be a three-layer structure (two layers of non-woven laminated to and interspersed with the elastic layer) or a two-layer structure (a layer of non-woven laminated to the elastic layer). In the following, the stretch laminate will be discussed as a three-layer structure, but this discussion is equally applicable to a two-layer structure.

[022] Stretch laminate nonwovens may be different or the same. Any non-woven fabric can be used. The nonwoven can have a base weight in the range of 5 to 25 grams per square meter (gsm) or 10 to 20 gsm.

[023] One (or the first) nonwoven may be a nonwoven by melt spinning or non-elastic, extensible spinning nonwoven. Fusion spinning nonwoven,

as used herein, it can be any melt spinning nonwoven, these melt spinning nonwovens (for example, SMS) may include, but are not limited to, SM, SMS, SSMMS, SMSMS, SMMMS, SMMS, SSMMSS , SSMMMSS, SSMMMSSS or any other combination of layers S and M, Ss representing a layer of the continuous spinning type and M representing a layer of the melting blowing type. The first nonwoven can be made of any material or polymeric material. In one embodiment, the first nonwoven is made of a material selected from the group of: polyolefin (PO - for example, polyethylene or polypropylene), polyester, polyamide (PA), acrylonitrile butadiene styrene (ABS), acrylic, polystyrene ( PS), fluorocarbon, polylactic acid (PLA) and their combinations. In another embodiment, the polyolefin can be polypropylene. In one embodiment, the first nonwoven may have an elongation perpendicular to the machine (CD) at break, in a range of 80 to 120% by 50 mm in width. In one embodiment, the first nonwoven may have an elongation in a direction perpendicular to the machine (CD) at maximum load in a range of 80 to 120% by 50 mm wide. In one embodiment, the nonwoven is a nonwoven of continuous spinning. The first nonwoven may be the nonwoven described in WO2016 / 107698 (= US2018 / 0002846), incorporated herein by reference. The first nonwoven can be the nonwoven described in WO2017 / 148865, incorporated herein by reference.

[024] The second non-woven (or optional) can be the same or different from the first non-woven. The second nonwoven may be a carded nonwoven, a spunlaced nonwoven, a continuous spinning nonwoven and / or a fusion spinning nonwoven. In one embodiment, the second nonwoven may be a carded nonwoven. In one embodiment, the second nonwoven may be a melt spinning nonwoven (e.g., SMS). In one embodiment, the second nonwoven may be a nonwoven of continuous spinning. In another embodiment, the second nonwoven may be a hydroentangled nonwoven. In yet another embodiment, the second nonwoven is a fusion fusion nonwoven (for example, SMS) selected from the group consisting of SM, SMS, SSMMS, SMSMS, SMMMS, SMMS, SSMMSS, SSMMMSS, SSMMMSSS or any another combination of layers S and M, S representing a layer of the continuous spinning type and M representing a layer of the melting blowing type.

[025] The elastic film (or material) can be any elastic film (or material). Elastic material means a material (or film) suitable to be stretched under the effect of a stretching force exerted in the lateral direction and to recover, substantially, its initial shape and dimensions after the release of the stretching force. For example, it can be a material that retains a residual or remaining deformation after elongation and release (the residual deformation also called “permanently set” or “SET”) of less than 30 percent, or less than 20 percent, or less than 15 percent, or less than 10 percent, or, for example, less than 5% of its initial dimension (before stretching) to an extent of 100 percent of its initial dimension, at room temperature (23ºC). SET can be measured as indicated in

Patent Application EP1783257, the content of which is incorporated by reference, and in particular in paragraphs [0056] to

[0062] of Publication EP1783257 Al, which shows in detail an example of a SET measurement. In one embodiment, the elastic film is made of a styrenic block copolymer. The elastic film can have a base weight in the range of 30 to 60 grams per square meter (GSM), or 40 to 60 gsm, and can have a thickness in the range of 75 to 125 micrometers (or microns). The thickness is measured when the elastic film is at rest (ie, not stretched). In one embodiment, the elastic film may have a modulus along a range of 50 to 350% elongation, in a range of 0.045 to 0.065 force N /% deformation for a 75 mm wide sample. In another embodiment, the module can be in a range of 0.050 to 0.060 N /% deformation for a 75 mm wide sample. The modulus is illustrated in Figure 3, where the X axis is the% deformation and the Y axis is the force (N).

[026] Stretch laminate layers can be laminated together. The lamination can be by any conventional technique. Conventional lamination techniques include, for example: adhesive bonding, thermal bonding, ultrasonic bonding, pressure bonding and combinations thereof. The non-woven fabric, in particular the first non-woven fabric, can have a base weight in the range of 5 to 25 g / mº. The nonwoven, in particular the first, can have the surface of the glued areas in the range of 5 to 20% (or 8 to 15%) of the total surface of the lateral, and the surface of the non-glued area of the nonwoven, in particular the first, it can be in the range of 80 to 95% of the total lateral surface. The non-woven fabric, in particular the first, can have individualized glued areas in the form of rods, each forming an angle of 90º in the direction of its length with the direction of the weft machine. The nonwoven, in particular the first, can have the surface of the glued areas arranged in such a way that, in the sense of the nonwoven machine, there are no uninterrupted regions along the nonwoven, while in the transverse direction of the nonwoven, the arrangement The glued area defines a plurality of uninterrupted regions that continuously extend along the plot.

[027] The stretch laminate can be activated. In one embodiment, the activation may be the progressive stretching of the laminate, for example, a ring cylinder, see, for example, US Patent Publication No. 2014/0378924, incorporated herein by reference. The amount of activation, measured as applied deformation (see US Patent Publication No. 2014/0378924), can be in the range of 130 to 180%. For further explanation of the applied deformation, refer to Figures 4A and 4B and Table 1 below. Figure 4A is an illustration of a 10-ring cylinder. Figure 4B is a schematic illustration of how rings 12 of the 10-ring cylinder intersect (looking in the machine direction (MD). The left side of Figure 4B does not show interlacing (that is, without progressive stretching of the stretch laminate 20), while the right side shows the interlaced rings (that is, progressive stretching of the stretching laminate 20). Table 1 is a graph showing the applied deformation (%) in the measure where the rings intertwine (the interlacing is quantified by the overlap or wrap (mm) of the rings).

Table 1 Block + Wrap (mm) Applied Deformation (3%) 37 228 mo 3.187

E 3 990 1 244 to 196 160 1.752 5.006 180 5.260 5th si T66

[028] In the following discussion of the physical properties of the stretch laminate, the stretch laminate has a continuous spinning polypropylene nonwoven, an elastic film, and the second nonwoven is a carded nonwoven. If other nonwoven seconds are used, the properties of the stretch laminate may change. These physical properties are determined using a 'constant rate of extension' tester (for example, Instron or MTS - commonly available) with the sample width mentioned below, a length of the extensometer (distance between jaws) as needed for sample testing concerned, and with a crosshead speed of 508 mm / min. For 10 N extension testing, the software (provided by the manufacturer) is programmed to output the elongation in mm at 10 N load. For the maximum load test, the software (provided by the manufacturer) is programmed to output the load on the sample failure.

[029] The stretch laminate can have a CD to N elongation (strength) in a range of 80 to 150% for a 50 mm wide sample.

[030] Stretch laminate can have a maximum failure load of at least 30 N for a 75 mm wide sample. At the maximum load in the failure of the stretch laminate, the elastic film can contribute at least 30% of the load. Alternatively, the elastic film can contribute in the range of 30 to 60% of the maximum load in the failure of the stretch laminate or 30 to 50% of the maximum load in the failure of the stretch laminate. At the maximum load in the failure of the stretch laminate, the elastic film can contribute at least 15 N of the maximum load of the stretch laminate. Alternatively, the elastic film can contribute in the range of 15 to 30 N of the maximum load in the failure of the stretch laminate or 15 to 25 N of the maximum load in the failure of the stretch laminate. For further explanation of the elastic film's contribution to maximum load, see Figures 5A and 5B. In these graphs, the top curve (with squares) represents the stress / strain curve of the stretch laminate, while the bottom curve represents the stress / strain curve of the elastic film.

[031] Stretch laminate rupture refers to openings in the first nonwoven after (or caused by) stretching of the stretch laminate, and where the openings cause the elastic layer to be exposed through the first nonwoven. The exposure of the elastic layer through the first non-woven fabric is, at least, detrimental to the appearance of the stretch laminate. In an embodiment of the present invention, the stretch laminate may not break when stretched. In another embodiment, the stretch laminate may have less than 10% breaks. In yet another embodiment, the stretch laminate can have less than 5% breaks. In still other embodiments, the stretch laminate can have: 0 to 10% ruptures, or 0 to 5% ruptures, or 5 to 10% ruptures (or any subset thereof).

[032] The procedure for measuring breaks, as used in this document, is set out below and with reference to Figures 6A, 6B (broken - Fr), 6C (not broken) and 7A (broken) and 7B (not broken). Procedure: 1) Cut a 50 mm wide sample of the stretch laminate (activated); 2) cut a 50 mm (width) x 40 mm (length) window into a piece of cardboard; 3) elongate the sample 100% and place (hold) the sample on the window with the side to be evaluated for ruptures facing upwards; 4) make a straight line in the transverse direction, see Figure 6A, anywhere along the width of the sample; 5) place a ruler along the straight line, see Figures 6B and 6C; 6) measure the length of each break in the length of 40 mm, see the arrows in Figure 6B, and add the measured lengths. In Figure 6B, the measured length added is 15 mm, so the break is 15 / 40x100 = 37%. In Figure 6C, the added measured length is 0 mm (or there is no broken non-woven area), so the break is 0%. A rupture is a place (or area) of the nonwoven where the nonwoven has broken, and the film is exposed through the nonwoven (that is, the film is naked); naked film refers to an area of the laminate where there is substantially no fiber covering the film. Figure 7A shows an approach view of a broken nonwoven (ruptures - Fr), and Figure 7B shows an approach view of an unbroken nonwoven. Note that Figure 7A is substantially fiber-free in a middle part of this photograph of the nonwoven.

[033] Alternative expressions of the invention include: A stretchable laminate for use in hygiene products comprises: a non-elastic, extensible melt spinning or continuous spinning nonwoven laminated with an elastic film; the nonwoven of fusion spinning or continuous spinning having an elongation CD (transverse to the machine) at maximum load in the range of 80 to 120% by 50 mm wide; the elastic film having a modulus of 0.045 to 0.065 of force N /% deformation over the range of 50 to 350% elongation; the stretch laminate is activated with a deformation applied in the range of 130 to 180%; it has a CD elongation at 10 N in a range of 80 to 150% for a 50 mm wide sample, and has fractures of less than 10% of the stretch laminate. Wherein: the stretch laminate further comprises a second nonwoven, nonwoven of continuous spinning or melt spinning and the second nonwoven interleaving the elastic film; the elastic film has a base weight in the range of 30 to 60 gsm (or 40 to 60 gsm); the elastic film has a thickness in the range of 75 to 125 micrometers; the elastic film modulus is in the range of 0.050 to 0.060 of force N /% deformation along the range of 50 to 350% of elongation; the stretch laminate has a maximum failure load of at least 30 N for the 75 mm wide sample; the elastic film contributes at least 30% of the maximum load in the failure of the stretch laminate, preferably the elastic film contributes in a range of 30 to 60% of the maximum load in the failure of the stretch laminate or in a range of 30 to 50% the maximum load in the failure of the stretch laminate; the elastic film contributes at least 15 N of the maximum load in the failure of the stretch laminate, preferably the elastic film contributes in a range of 15 to 30 N of the maximum load in the failure of the maximum laminate or in a range of 15 to 25 M maximum load in the failure of the stretch laminate.

[034] A stretch laminate for use in hygiene products comprises: a non-woven, non-elastic, extensible spinning non-woven fabric, a second non-woven fabric and an elastic film sandwiched between them; the nonwoven of continuous spinning or fusing spinning having a CD elongation at maximum load in the range of 80 to 120% by 50 mm wide; the elastic film having a base weight in the range of 30 to 60 gsm (or 40 to 60 gsm), a thickness in the range of 75 to 125 micrometers, a module of 0.045 to 0.065 of force N /% deformation along the range of 50 to 350% elongation; the stretch laminate is activated with a deformation applied in the range of 130 to 180%, resulting in a stretch laminate with a CD elongation at 10 N in a range of 80 to 150% for a 50 mm wide sample, a maximum load on at least 30 N failure for the 75 mm wide sample, and has less than 10% of the total broken stretch laminate. Where: the second nonwoven is a non-elastic, extensible carded nonwoven, the maximum load on failure of the stretch laminate is in the range of 30 to 50 N or the maximum load on failure of the stretch laminate is in the range of 40 to 50 N ; the nonwoven of continuous spinning or fusion spinning is made of a material selected from the group of: polypropylene, polyester, polyethylene, polyamide (PA), acrylonitrile butadiene styrene (ABS), acrylic, polystyrene (PS), cellulosic, fluorocarbon, polylactic acid (PLA) or their combinations.

[035] The invention can be further illustrated by the following non-limiting examples. Examples

[036] The following tables describe several stretch laminates and their first non-woven laminates (Side 1). Table 2 Wiring Base Weight ”Maximum Load Bonding? To be continued! Maximum Elongation CDº CD? EEE ES Es aa EEB AE Es T6 a 20 A - Fitesa CD Rod Supersoft B - Texbond Blowbond (code KJ C - Berry (PGI code 0111-26H) 1 -— 50 mm wide 2? - grams per square meter (gsm) 3-8 1 - N / 5cm —-% area Table 3 Laminate | Side | Side [Block | Elongation Elongation? [Condition | Load on | Increase 1 2 activation? (Mm) (&) of No | Fabric failure | Laminate | Continuous (O) Wiring (O) Load Failure (O) Film 1 - Film formula with high stretchable capacity: Film 200B Lo EE a te a vo Fo e Es Tas a E va va | Film 2 - Low-capacity film formula: Film 2120 Ls from dp to oo to Ls Je lp »ie Dao to E Da | 6) A - CD Rod tape at 18 gsm B - Texbond Blowbond at 18 gsm C - Berry to 18 gsm D - non-woven carded to 22 gsm CF - non-woven cover film F - non-woven breaks! - = A 10 N, sample 50 mm wide, 40 mm long, mm? - At 10 N, sample 50 mm wide, 40 mm long, mm? - Increased load on failure with Film 2

[037] The present invention can be incorporated in other forms, without departing from the spirit and its essential resources, and, therefore, reference should be made to the attached claims, instead of the previous description, as indicated in the scope of the invention .

Claims (15)

1. Stretchable laminate for use in hygiene products, characterized by the fact that it comprises: a non-elastic, extensible melt spinning or continuous spinning nonwoven laminated with an elastic film; and the stretchable laminate is activated, has a 10 N crosswise elongation (CD) in a range of 80 to 150% for a 50 mm wide sample, and has less than 10% breaks in the stretchable laminate. 2. Stretch laminate, according to claim 1, characterized by the fact that it also comprises a second non-woven fabric, the non-woven fabric and the second - “non-woven fabric interleaving the elastic film. 3. Stretch laminate, according to claim 1, characterized by the fact that the elastic film has a base weight in the range of 30 to 60 grams per square meter (gsm) or 40 to 60 gsm. 4, Stretch laminate, according to claim 1, characterized by the fact that the elastic film has a thickness in the range of 75 to 125 micrometers. 5. Stretch laminate according to claim 1, characterized by the fact that the stretch laminate has a maximum failure load of at least 30 N for the 75 mm wide sample. 6. Stretch laminate according to claim 5, characterized by the fact that the elastic film contributes at least 30% of the maximum load in the failure of the stretch laminate, or the elastic film contributes in a range of 30 to 60% of the load maximum in the failure of the stretch laminate, or the elastic film contributes in a range of 30% to 50% of the maximum load in the failure of the stretch laminate. 7. Stretch laminate, according to claim 5, characterized by the fact that the elastic film contributes at least 15 N of the maximum load in the failure to which the elastic film contributes, or the elastic film contributes in a range of 15 to 30 N of the maximum load in the fault to which the elastic film contributes, or the elastic film contributes in a range of 15 to 25 N of the maximum load in the fault. 8. Stretch laminate, according to claim 1, characterized by the fact that the nonwoven of direct spinning or fusing spinning has a CD elongation (transversal to the machine) at maximum load in the range of 80 to 120% by 50 mm wide. 9. Stretch laminate according to claim 1, characterized by the fact that the elastic film has a modulus of 0.045 to 0.065 of force N /% deformation along the range of 50 to 350% of elongation or a modulus of 0.050 at 0.060 strength N /% strain over the range of 50 to 350% elongation. 10. Stretch laminate according to claim 1, characterized by the fact that the stretch laminate has a deformation applied in the range of 130 to 180%. 11. Method for reducing or eliminating the breakage of a nonwoven in a stretch laminate used in hygiene products, after the stretch laminate has been stretched, characterized by the fact that it comprises the steps of: providing a stretch laminate having a nonwoven of continuous spinning or non-elastic fusion spinning, extensible, laminated with an elastic film, the stretch laminate is activated and has a CD elongation at 10 N in a range of 80 to 150% for a 50 mm wide sample, stretch the stretch laminate, and the stretch laminate having fractures (Fr) of less than 10% of stretch laminate. Method according to claim 11, characterized in that it further comprises a second nonwoven, the melt spinning or continuous spinning nonwoven and the second nonwoven interleaving the elastic film. 13. Method, according to claim 11, characterized by the fact that the elastic film has a base weight in the range of 30 to 60 grams per square meter (gsm) or 40 to 60 gsm. 14. Method, according to claim 11, characterized by the fact that the elastic film has a thickness in the range of 75 to 125 micrometers. 15. Method, according to claim 11, characterized by the fact that the nonwoven of direct spinning or fusing spinning has an elongation in the transversal direction to the machine (CD) at the maximum load in a range of 80 to 120% by 50 mm.